📘 Chapter 19: Blood – Full Simplified Study Notes (27 Slides) ⸻ Slide 1: Cardiovascular System • Cardiovascular system = heart, blood, blood vessels. • Blood’s job: • Delivers nutrients, hormones, oxygen, and chemical messages. • Carries immune cells to fight infections. • Why it matters: Without this transport system, cells would starve and toxins would build up. • Analogy: Like UPS + garbage service → delivers packages (nutrients, O₂) and removes trash (waste, CO₂). ⸻ Slide 2: Whole Blood • Whole blood = plasma + formed elements. • Hematocrit: percentage of blood volume made of cells. • Plasma: watery fluid. • Key properties of blood: • Temp: 38°C (100.4°F) → warmer than body surface. • Thickness: 5x thicker than water. • pH: ~7.4 (slightly alkaline). • Volume: Men = 5–6 L, Women = 4–5 L. • About 7% of body weight. • Example: If someone weighs 150 lbs, about 10 lbs of that is blood. ⸻ Slide 3: Blood Plasma • Plasma = liquid with proteins + solutes. • Proteins: • Albumins: keep water inside blood vessels (prevent swelling). • Globulins: antibodies → defense. • Fibrinogen: forms clots. • Other solutes: • Electrolytes: Na⁺, K⁺, Cl⁻, HCO₃⁻ (important for nerves/muscles). • Nutrients: glucose, fructose, amino acids. • Wastes: urea, uric acid. • Analogy: Plasma = soup broth carrying salt, sugar, proteins, and waste. ⸻ Slide 4: Formed Elements • Red Blood Cells (RBCs / erythrocytes): 99.9% of all blood cells. • RBC count: Men = 4.5–6.3 million/μL, Women = 4.2–5.5 million/μL. • Platelets: fragments needed for clotting. • White Blood Cells (WBCs / leukocytes): fight disease. • Think: Plasma is the liquid, formed elements are the “stuff floating inside.” ⸻ Slide 5: RBC Structure • RBCs lose their nucleus & organelles. • Consequences: • Can’t divide. • Can’t make proteins or repair. • Only use glycolysis (anaerobic metabolism) → no oxygen needed for energy. • Analogy: Like delivery trucks with no engine shop → they drive until they break down. ⸻ Slide 6: RBC Lifespan • RBCs have no nucleus, mitochondria, ribosomes → no repair. • Rely on glycolysis for energy. • Live about 120 days. • Must be recycled by spleen/liver. • Example: Like a disposable battery that runs until it dies. ⸻ Slide 7: RBC Shape & Function • Shape = biconcave disc (doughnut-like, thin middle). • Benefits: • High surface area → better oxygen exchange. • Can stack like coins → smooth flow. • Flexible → squeeze through tiny capillaries. • Analogy: Like a flexible frisbee that can bend and stack. ⸻ Slide 8: Hemoglobin • Main protein inside RBC. • Structure: • 2 alpha chains + 2 beta chains. • Each has heme group with iron atom (Fe). • Function: Iron binds oxygen → carries it around body. • Why recycle? Iron is valuable, so old RBCs get broken down to save it. • Analogy: Hemoglobin = oxygen backpack. ⸻ Slide 9: RBC Lifecycle • Starts from hemocytoblast (stem cell). • Branches into: • Myeloid stem cells: make RBCs + some WBCs. • Lymphoid stem cells: make lymphocytes. • Think: Hemocytoblast = tree trunk, RBCs and WBCs = branches. ⸻ Slide 10: RBC Production (Erythropoiesis) • Erythropoiesis = making RBCs. • Embryo: 1st 8 weeks = yolk sac → later liver, spleen, thymus, bone marrow. • Adult: red bone marrow only (vertebrae, sternum, ribs, skull, pelvis, ends of long bones). • Nutrients needed: amino acids, iron, vitamins B12, B6, folic acid. • Analogy: RBCs = cookies, bone marrow = kitchen, iron + vitamins = ingredients. ⸻ Slide 11: RBC Production Control • Controlled by erythropoietin (EPO). • Made by kidneys/liver when low oxygen (hypoxia). • Effects: • Increases stem cell division. • Speeds up hemoglobin production. • Blood doping: Athletes take EPO or reinfuse RBCs → more oxygen for muscles. • Risk: thicker blood → clots, strokes. • Analogy: EPO = coach yelling “make more RBCs!” ⸻ Slide 12: Blood Types • RBCs have antigens on membranes (A, B, AB, O). • Rh factor = + or –. • Plasma has antibodies (agglutinins): attack foreign antigens → cause clumping (agglutination). • Universal donor = O–. • Analogy: Blood type = ID card. If ID doesn’t match, antibodies attack. ⸻ Slide 13: RBC Summary • Know: • How typing works. • How RBCs are made. • What controls them. • Why they live 120 days. • How they’re broken down. • Analogy: RBCs = delivery trucks with expiration dates. ⸻ Slide 14: WBC Basics • WBCs = leukocytes. • Have nuclei, organelles, no Hb. • Functions: fight pathogens, remove wastes, destroy abnormal cells. • Only in blood briefly → then move into tissues. • Analogy: WBCs = body’s police force. ⸻ Slide 15: Neutrophils • 50–70% of WBCs. • Nucleus 2–5 lobes. • First responders → attack bacteria. • Use phagocytosis + enzymes. • Die quickly → pus = dead neutrophils + bacteria. • Analogy: Neutrophils = foot soldiers. ⸻ Slide 16: Basophils • <1% WBCs. • Release histamine (dilates vessels, causes swelling/redness). • Release heparin (prevents clots). • Trigger inflammation → work with mast cells. • Analogy: Basophils = fire alarms. ⸻ Slide 17: Eosinophils • 2–4% WBCs. • Stain red-orange. • Bi-lobed nucleus. • Kill parasites, respond to allergies. • Release toxic chemicals (nitric oxide, enzymes). • Help control inflammation. • Analogy: Eosinophils = exterminators. ⸻ Slide 18: Monocytes • 2–8% WBCs. • Largest WBC, kidney-shaped nucleus. • Become macrophages in tissue. • Eat large pathogens, dead cells. • Call fibrocytes → scar tissue. • Analogy: Monocytes = garbage trucks. ⸻ Slide 19: Lymphocytes • 20–30% WBCs. • Big nucleus, little cytoplasm. • Most live in lymph tissue. • Types: • T cells: attack infected cells. • B cells: make antibodies. • NK cells: kill cancer/virus cells. • Analogy: Lymphocytes = special forces. ⸻ Slide 20: WBC Production • From hemocytoblasts. • Myeloid stem cells: all except lymphocytes. • Lymphoid stem cells: lymphocytes. • Colony-Stimulating Factors (CSFs): • M-CSF = monocytes. • G-CSF = granulocytes. • GM-CSF = granulocytes + monocytes. • Multi-CSF = RBCs + WBCs + platelets. • Analogy: CSFs = managers assigning jobs. ⸻ Slide 21: Platelets • Fragments of cells, no nucleus. • Lifespan = 9–12 days. • Removed by spleen. • 2/3 stored for emergencies. • Analogy: Platelets = emergency patch kits. ⸻ Slide 22: Platelet Functions 1. Release clotting chemicals. 2. Form platelet plug at damage site. 3. Contract (actin + myosin) → shrink clot, close wound. • Analogy: Platelets = patch team pulling duct tape tight. ⸻ Slide 23: Hemostasis • Definition: stopping bleeding. • 3 phases: vascular, platelet, coagulation. • Analogy: Like fixing a leaking pipe step by step. ⸻ Slide 24: Vascular Phase • Vessel wall contracts (vascular spasm). • Endothelial cells: • Expose basement membrane. • Release endothelins → stimulate contraction/healing. • Become sticky → platelets attach. • Analogy: Pinch a hose to slow the leak. ⸻ Slide 25: Platelet Phase • Platelets stick to exposed collagen. • Form platelet plug (15 sec after injury). • Release chemicals: ADP, thromboxane A₂, serotonin, Ca²⁺, PDGF. • Feedback prevents over-clotting. • Analogy: Like putting your hand over a hole until repair arrives. ⸻ Slide 26: Coagulation Phase • Chain reaction of clotting factors. • Fibrinogen → fibrin (forms net). • Common pathway: 1. Factor X → prothrombinase. 2. Prothrombin → thrombin. 3. Fibrinogen → fibrin. • Clot retraction pulls vessel edges together. • Analogy: Casting a fishing net over the leak. ⸻ Slide 27: Fibrinolysis & Clotting Needs • Fibrinolysis: clot dissolves after healing. • t-PA → activates plasminogen → plasmin → digests fibrin. • Requirements for clotting: • Calcium (Ca²⁺): needed in all clotting steps. • Vitamin K: liver makes clotting factors; comes from food + gut bacteria. • Deficiency = bleeding problems. • Analogy: Once pipe is repaired, cut away the net (clot)

Cardiovascular System

The system consisting of the heart, blood, and blood vessels that delivers nutrients, hormones, oxygen, and immune cells.

Whole Blood

The entirety of blood consisting of plasma and formed elements, with hematocrit indicating the percentage of blood volume made of cells.

Plasma

The liquid component of blood containing proteins and solutes, serving essential functions in the transport of materials.

Red Blood Cells (RBCs)

Erythrocytes that constitute 99.9% of all blood cells, crucial for oxygen transport.

Hematocrit

The percentage of blood volume that is made up of cells.

Erythropoiesis

The process of producing red blood cells, occurring in the red bone marrow of adults.

Hemoglobin

The main protein in red blood cells that binds oxygen for transport throughout the body.

White Blood Cells (WBCs)

Leukocytes that play a key role in the immune response by fighting pathogens and removing waste.

Platelets

Cell fragments essential for blood clotting, with a lifespan of 9-12 days.

Hemostasis

The process of stopping bleeding, which consists of vascular, platelet, and coagulation phases.

Fibrinolysis

The process of clot breakdown after healing, involving the digestion of fibrin.

Antigens

Molecules on the surface of red blood cells that determine blood type and can trigger immune responses.

Erythropoietin (EPO)

A hormone produced by the kidneys/liver that stimulates the production of red blood cells in response to low oxygen levels.

Neutrophils

The most abundant type of white blood cell, essential for responding to bacterial infections.

Lymphocytes

A type of white blood cell that includes T cells and B cells, crucial for adaptive immunity.

Coagulation Phase

The phase in hemostasis involving a series of clotting factors that lead to the formation of a fibrin net.

Basophils

A type of white blood cell that releases histamine and heparin, involved in inflammatory responses.

Eosinophils

White blood cells that respond to allergies and parasitic infections, releasing toxic substances.

Monocytes

The largest type of white blood cell that differentiates into macrophages to engulf pathogens and debris.